ISO 5278-1980 PDF

Full title and description

St ISO 5278-1980 — Benzene — Determination of crystallizing point. Specifies a laboratory method for measuring the temperature at which benzene crystallizes (to the nearest 0.01 °C), including use of a test portion saturated with water, an adjustment to obtain the value for the anhydrous material, requirements for the thermometer and its checking, and the arrangement of the measurement apparatus.

Abstract

This international standard gives a procedure to determine the crystallizing (freezing) point of benzene with high precision (0.01 °C). The method covers preparation of the test portion (water-saturated), application of a correction to report the anhydrous crystallizing point, the specification and verification of the thermometer, and an illustrative test apparatus arrangement.

General information

• Status: Withdrawn (international standard no longer active).
• Publication date: April 1980 (Edition 1, 1980-04).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 71.080.15 (Aromatic hydrocarbons / benzene-related test methods).
• Edition / version: Edition 1 (1980).
• Number of pages: 3 pages.

Scope

The standard applies to the laboratory determination of the crystallizing point of benzene. It specifies the test portion conditions (water-saturated sample), the measurement precision (0.01 °C), how to correct the measured value to report the anhydrous crystallizing point, the thermometer performance and checking procedure, and the basic arrangement of the crystallizing-point apparatus used for the test.

Key topics and requirements

• Definition of crystallizing point and required measurement precision (0.01 °C).
• Preparation of test portion — specification for water-saturated samples and correction to anhydrous values.
• Thermometer technical requirements and a procedure for verification/checking of thermometer accuracy.
• Description/figure of the recommended crystallizing-point measurement apparatus (Dewar-style cooling bath and sample arrangement).
• Precautions for handling benzene (toxicity and flammability warnings implicit in the method).

Typical use and users

Used by analytical chemists and laboratories performing physicochemical characterization of aromatic hydrocarbons, regulatory or quality laboratories in petrochemical and chemical production, and standards bodies that compare or archive historic test methods. The method is primarily applicable when precise crystallizing-point data for benzene are required for research, quality control or reference purposes.

Related standards

Standards and methods for freezing/crystallizing point determination and related aromatic hydrocarbon test methods (other ISO methods under ISO/TC 47) are relevant for cross-reference; national members and standards organizations have archived or replaced various test methods. Note: ISO 5278:1980 itself has been withdrawn and users should consult current ISO/TC 47 publications or national methods for up-to-date procedures.

Keywords

benzene; crystallizing point; freezing point; determination; thermometer calibration; dew-point apparatus; aromatic hydrocarbons; ISO 5278; test method; physicochemical property.

FAQ

Q: What is this standard?

A: ISO 5278:1980 is an International Standard titled "Benzene — Determination of crystallizing point" that specifies a laboratory method to measure the crystallizing (freezing) point of benzene to 0.01 °C.

Q: What does it cover?

A: It covers sample condition (water-saturated test portion), the measurement technique and apparatus arrangement, thermometer requirements and checking, and how to apply a correction to obtain the anhydrous crystallizing point from the measured value.

Q: Who typically uses it?

A: Analytical and quality-control laboratories in chemical and petrochemical industries, researchers needing precise benzene property data, and standards organizations for method harmonization or historical reference.

Q: Is it current or superseded?

A: ISO lists ISO 5278:1980 as Withdrawn. Some national catalogues (for example the Estonian standards body) note withdrawal effective 27 May 2002, while other commercial records show later withdrawal listings — in any case the standard itself is not current and users should consult ISO/TC 47 or their national standards body for any replacement or updated methods.

Q: Is it part of a series?

A: It was developed under ISO/TC 47 (Aromatic hydrocarbons) and stands as a single-method standard for benzene crystallizing point; related test-method standards for aromatic hydrocarbons and other properties exist within the same technical committee series.

Q: What are the key keywords?

A: Benzene, crystallizing point, freezing point, thermometer calibration, aromatic hydrocarbons, ISO 5278, analytical method.